The process of cutting straight, curved, intricate and/or closed-loop contours in workpieces is well known and has especially been used in the traveling-wire electroerosion machining art. In this process, a workpiece is commonly carried securely on a work support and a continuous electrode wire continuously dispensed from a supply spool is axially passed through the workpiece and continuously collected onto a takeup side. Since the electrode wire is caused to travel through the workpiece, the work support which has a supporting surface commonly extending horizontally cannot carry the entire lower area of the workpiece on this supporting surface. A machining region of the workpiece must be left unsupported by the supporting surface to allow a desired cut to be formed therein. The weight of this region of the workpiece and that of the remainder thereof may equally apply on the work support initially. As cutting advances, however, so that the workpiece is progressively divided into two portions with respect to the advancing cutting path, it will be apparent that while one portion is held supported by the work support, the other tends to fall off the one portion by its own weight due to gravity. It will be readily apparent that an actual drop-off of the unsupported portion takes place when the two portions are severed from one another and this may occur even before the preprogrammed cutting path is completely finished and that the drop-off may break the cutting electrode wire and may seriously damage the workpiece.
A measure commonly employed in the art heretofore to avoid this problem is that when machining approaches the end point of the cutting path, the operator interrupts the operation of the machine, places an additional work support in the form of a block of suitable height and width supporting workpiece against the gravity acting on the portion tending to fall off, and restarts the machine to allow the two portions to be severed by the continued wire-cutting operation. The gravity-resisting block as the additional work support may be replaced by a permanent magnet briged across the severed portions or an adhesive applied in the cut groove. Obviously, these conventional procedures are bothersome and inefficient as far as they entail the operator's attention and labor. It should also be noted that the actual drop-off is not the sole problem arising from the unsupported portion of the workpiece being divided. It has now been found that even before it reaches a severing point, the unsupported portion tending to fall off the other portion causes a deflection of the workpiece to the extent that the cutting zone is dislocated and hence the cutting accuracy is significantly affected.